After my years of playing Counter Strike Source, I'm used to both Teamspeak and Ventrilo and in my opinion, based on sound quality and ease of use Ventrilo is far better.
The servers are cheap and they are really easy to set up, but that really depends on who you bought the server from. A lot of providers set the server up for you and give you a web based control panel to change whatever you want with ease.
I used to cruise... until I realised how much of a waste of time it was. I think its just addictive, you see guys driving around in faster cars and you think "OMG THOSE GUYZ R PR0" and devote your life to be able to drive them.
Then you go to a real server.
I can see why a lot of people would enjoy it, mainly because i used to enjoy it myself, so I have nothing against it at all.
As I'm sure someone would tell me, if I don't like it, dont play it